Field of the Invention
The present invention relates to an elevator door safety lock system which is configured to safely and effectively lock the doors of an elevator when it is not properly aligned at a designated floor opening. In particular, the elevator door safety lock system provides for effective, safe and secure operation even during power failures and within the crammed and often dirty elevator shaft environment, all in a manner which is substantially easy to ensure effective installment and operation.
Description of the Related Art
An important safety characteristic associated with the operation of nearly all elevators is ensuring that the elevator doors do not open at inappropriate location in the hoistway. In particular, safety evaluations over the years have concluded that in order to preserve maximum safety to the occupants of an elevator, it is imperative that the elevator doors remain in a closed position whenever the elevator is not properly aligned with a floor opening at which safe ingress and egress can be achieved. This includes during travel of the elevator between floor openings, as well as in a situation where an elevator gets stuck between floors, as substantial hazards can occur if occupants of an elevator attempt to open the doors and/or exit the elevator at inappropriate location within the hoistway. Of course, it is understood that for emergency circumstances, any safety lock system must be capable of being exteriorly released, such as during a rescue procedure, however, that release should ultimately be achieved only from the exterior of the car by rescue personnel who have ensured that it is safe for the doors to be opened and for the occupants to be evacuated, or only under controlled or limited circumstances from within the elevator car.
In order to achieve this important safety measure, there have been a variety of different locks and latches developed over the years in order to maintain the elevator door is secure. A substantial drawback associated with these existing latching systems, however, relates to the potential for significant malfunction if power is interrupted to the lock mechanism, such as during a power outage. For example, traditional safety latches are configured to be either closed or open when energized, and to move to an opposite state when de-energized. As a result, if the power to the locking system should be cut for any reason, the door lock will automatically revert to the de-energized state, which in most cases involves unlocking the elevator doors. As can be appreciated, if the cause for an elevator malfunction, such as being trapped between floor openings is a result of a power outage, that very same power outage would also result in counteraction of a primary safety measure associated with the operation of the elevator. Further, even though entirely mechanical locking mechanisms may be employed, with today's modern technology it is generally preferred that appropriate sensors be incorporated into the locking mechanism such that a central control is able to recognize if the doors are locked or unlocked, as well as various other safety checks. Accordingly, for these reasons it would be highly beneficial to provide an elevator door safety lock system which is not subject to power failures or power outages allowing for the doors to open, thus potentially leading to a hazardous situation.
In addition to the above recited difficulties associated with lock malfunctions as a result of power interruption or power outages, another significant concern associated with existing elevator door locking systems relates to wear and tear of the locking mechanism. Specifically, because those locking systems must necessarily be maintained in an energized state for extended periods of time, the mechanism will wear at a much more rapid pace than may be ideal, thus resulting in potentially hazardous malfunctions, or necessitating frequent repairs and/or maintenance checks. Accordingly, it would be beneficial to provide a safety door lock system which securely locks the door with a mechanism that is not only safe and secure, but which will also have a long life and reduced potential for malfunction.
Still another difficulty associated with existing locking systems relates to malfunctions in recognizing when the elevator is properly aligned with a floor opening. In particular, many existing door locking systems determine proper alignment by incorporating a contact type system which tells the door lock when the elevator is properly aligned with a floor opening because a physical contact is made. Unfortunately, such contact systems, while not generally susceptible to malfunction as a result of power interruptions or power outages, are subject to significant wear over time, and as a result of friction, dirt, corrosion, and normal debris or oil/lubricants that may be present in the elevator shaft and can interfere with the contact. As a result, in order to ensure that the locking system will ultimately function properly, frequent cleaning and/or changing of the contacts is typically required, especially as a result of the wear characteristic resulting from continuous contacting and uncontacting. Moreover, although some in the industry have attempted to utilize visual indicators of the elevator's positioning, it has been seen that those visual indicators are also susceptible to power outages or power interruptions, especially due to the power requirements associated with the LEDs or electric eyes that typically comprise such visual sensors, but more so because visual sensors are especially susceptible to dirt and grime within the elevator shaft which may occlude lenses, lights and/or markings. As a result, it would be highly beneficial to provide a vertical position sensor which is configured in such a manner that it does not require the strong continuous power source that would be susceptible to power outages or power malfunctions, and which is also configured in a manner whereby it can operate for extended periods of time without repair, replacement or cleaning, and is minimally, if at all susceptible to the dirty or grimy operating environment typically associated with the interior of an elevator shaft.